Oven conveyor



May 31, 1966 E. F. KowALlK OVEN CONVEYOR Filed Nov. 21, 1962 A T TORNEI Y Om mn.

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United States Patent O 3,253,345 OVEN CONVEYOR Eugene Franci Kowalik, Ridgefield, Conn., assignor to Diamond International Corporation, a corporation of Delaware Filed Nov. 21, 1962, Ser. No. 239,301

4 Claims. (Cl. 34-21) The present invention relates to oven dryers and has particular reference to an oven conveyor that increases the drying time without increasing the length of the conveyor.

With the conveyor mechanism of the present invention it is possible to provide a more efficient drying process.

Using the conveyor mechanism of the present invention a much shorter than conventional oven may be used for the drying of articles passing through the oven at a certain speed, thereby resulting in a reduction in the use of building space. e

In the event that the conveyor mechanism of the present invention is installed in the longer conventional ovens, then a greater speed may be used to move the articles being dried than could be used with conventional conveyors in obtaining removal of the same amount of moisture from these articles.

Also,with the new conveyor mechanism the articles being dried are prevented from falling ofI due to insuflicientv initial drying.

Broadly there are two types of drying. One is called free drying and the other is called form drying. In free drying, the articles to be dried rest on a tray freely and are passed through a tunnel or chimney where the hot air -impinges on the article and dries it. Articles dried on forms, as with the present invention, are subject to much less warpage than freely dried articles.

As the article is dried it has a certain tendency to shrink which causes it to hold tighter onto the form. In the device of the present invention the form dryer is so arranged that the articles to be dried are held in an upright position and cannot fall off the forms during the rst two passes through the drying oven when the articles are Wettest and have not yet shrunk tightly to the forms. After two more additional passes through the oven for more complete drying, the dried article is removed from the form and the form moves into a position to receive another wet article.

A further advantage of the present invention is that each location or station on the conveyor may hold twice as many articles as the conventional conveyor.

Basically, the present invention provides a new and improved conveyor means for use in drying ovens wherein a substance such as wet pulp, which may be dried to form cartons, is placed on forms which pass through an oven four times, with support under the pulp during the first two passes when in its wettest state, and the form inverted when the pulp is dry and firmly on the form and ready for removal from the drying form.

With the arrangement of the present invention, a double track is provided at one end of the conveyor to keep the pulp on a form facing upward during the first two runs through the oven during the initial drying of the pulp or similar substance.

These as well as further advantages which' are inherent in the invention will become apparent from the following description, reference being had to the accompanying drawings wherein:

FIG. 1 is an overall view of the mechanism of the present invention;

FIG. 2 is a view of ejection mechanism taken substantially on line 2-2 of FIG. 1; and

FIG. 3 is a schematic view showing the path of travel on the conveyor of an article being dried in an oven.

3,253,345 Patented May 31, 1966 FIG. l illustrates the apparatus of the present invention in relation to the associated apparatus with which it may be used in the manufacture of egg cartons. In the process, the wet pulp is drawn onto forms 101 mounted on a rotary means 11 by suction means and then carried to the conveyor 12 and transferred from the form 10 on the rotary means 11 to form 13 on conveyor 12. A conventional means to accomplish this transfer is by the application of air pressure through the form 10 and suction through the form 13 thereby transferring the wet pulp from rotary means 11 to conveyor means 12.

Form 13 is vpart of unit 20 on the conveyor which is shown in somewhat more detail in FIG. 2 as a sectional view along line 2 2 of FIG. 1. Unit 20 of conveyor 12 has forms 21 and 22 mounted on opposite faces of unit 20. Plungers 23 are mounted so as to be in a position to project through form 21. As shown in FIG. 2, springs 24 hold plungers 23 in a position so as not to disturb the wet pulp on its travels around conveyor 12 until it is time to eject the dried carton from the form on conveyor 12. Unit 2t) is moved around conveyor 12 on rollers 25 which ride in guide rail 26.

Referring again to FIG. 1 it will be noted that after the transfer of the wet pulp to form 13 on conveyor 1,2, the form as part of unit 20 is moved with the unit into oven 14. As shown schematically in FIG. 3, the wet pulp 30 just transferred at the wet end transfer station is on form 13 which faces upward during the first horizontal run through oven 14 thereby having a support under wet pulp 36 during its wettest period when it is most likely to fall from form 13. Path 31 in FIG. 3 depicts the initial path of the wet pulp on conveyor 12. At the end of the horizontal run guide rail 26 comes a Y junction wherein the front set of rollers move along guide rail 16a and the back set of rollers move along guide rail 16h in order to allow unit 20 to descend to a lower level of conveyor 12 along path 32 while maintaining wet pulp 30 in a level position still supported by form 13. At the lower level of con veyor 12 the pulp travels horizontally through the length of oven 14 again along path 33 with the still wet pulp 30 supported by form 13. Upon reaching the end of the second horizontal run along path 33 form 13 moves in a semi-circular path 34. Form 13 is now in a position facing downward. Since the first two runs through oven 14 have dried pulp 30, to some extent the pulp has shrunk so as to form a tight fit over form 13 whereby pulp 30 will maintain its hold on form 13 throughout the remaining travel on conveyor 12 along horizontal path 35, vertical path 36 and horizontal path 37 to the take-off station at position 38.

At take-off station position 38 the dried egg carton or other pulp coniiguration 30 is removed from Vform 13 which is positioned in a downward facing direction. The mechanism for accomplishing this as shown in FIG.

2 has been discussed previously to some extent. At this position a downward acting mechanism 39 moves through open slots in unit 20 to contact member 27 attached to plungers 23 which moves plungers 23 through form 22 in opposition to the forces exerted by springs 24. In the described case, form 13 is equivalent to form 22 and positioned as shown in FIG. 2. Pulp 30 is thereby removed as shown.

Pulp 30 in the configuration of an egg carton in the example illustrated drops onto conveyor 35 and is then carried to a collection station.

Form 13, now emptied of pulp 30 is moved along toward the Wet end transfer station to receive another load of wet pulp which it will carry through the drying cycle. The form on unit 20 on the opposing face to form 13 is carrying pulp which has reached path 34 On its drying cycle in oven 14.

It will be obvious to those skilled in the art that various changes may be made without departing from the spirit of the invention and therefore the invention is not limited to what is shown in the drawings and described in the specication but only as indicated in the appended claims.

What is claimed is:

1. A method of drying an article on a relatively short conveyor which comprises transferring a wet article to an outside article holder on a drying station on the conveyor, passing said drying station in one direction through a drying tunnel, moving said drying station around a loop in the conveyor to a lower level while retaining the same relative position parallel to the horizontal, thereby changing the direction of movement of said drying station on the conveyor, passing said drying station in an opposite direction through a drying tunnel, moving said drying station to an upper level while reversing its relative position to the horizontal, passing said drying station in the first mentioned direction through a drying tunnel, again moving said drying station around a loop on the conveyor to a lower level while retaining the same relative position parallel to the horizontal, removing a dried article from an outside holder on said drying station, and moving said drying station to a position to receive another wet article.

2. A conveyor for a dryer in which articles being dried make two loops through a drying tunnel comprising:

a plurality of movable drying stations,

guide means forming a loop of at least rst, second, 30

third and fourth portions in successive rotative order describing a path for said drying stations, each of said drying stations having two oppositely facing article holders positioned so as to face one of said article holders toward the outside of the loopv when the other of said article holders is facing toward the inside of the loop, means for transferring an article to an outside facing holder at each of said stations before passing said station through the drying tunnel in one direction along said tirst portion of said guide means, 4means to retain said holder in the same relative position to the horizontal while each of said stations changes direction on said second portion of said guide means, means to reverse the relative position of said holder in relation to the horizontal while each of said stations changes direction on said fourth portion of said guide means, and means of removing an article from an outside facing holder at each of said stations after passing said station with the article in said holder in a path substantially twice over each of said lirst and third portions of said guide means. 3. The conveyor in accordance with claim 2 further characterized by said means for transferring an article to an outside facing holder being a means to transfer a wet 2O article.

4. The conveyor in accordance with claim 2 further characterized by said means of removing an article from an outside facing holder disengaging the article from said drying station with said drying station positioned at a 25 lower level on said guide means and said outside facing article holder facing downward.

References Cited by the Examiner UNITED STATES PATENTS 1,698,545 4/1927 Hill 34-208 2,512,356 6/1950 Massiello 198-138 2,807,892 l0/l957 Gerrish 34--208 2,879,696 3/1959 COX 18-4 WILLIAM F .ODEA, Primary Examiner.

NORMAN YUDKOFF, Examiner.

F. E. DRUMMOND, Assistant Examiner. 

1. A METHOD OF DRYING AN ARTICLE ON A RELATIVELY SHORT CONVEYOR WHICH COMPRISES TRANSFERRING A WET ARTICLES TO AN OUTSIDE ARTICLE HOLDER ON A DRYING STATION ON THE CONVEYOR, PASSING SAID DRYING STATION IN ONE DIRECTION THROUGH A DRYING TUNNEL, MOVING SAID DRYING STATION AROUND A LOOP IN THE CONVEYOR TO A LOWER LEVEL WHILE RETAINING THE SAME RELATIVE POSITION PARALLEL TO THE HORIZONTAL, THEREBY CHANGING THE DIRECTION OF MOVEMENT OF SAID DRYING STATION ON THE CONVEYOR, PASSING SAID DRYING STATION IN AN OPPOSITE DIRECTION THROUGH A DRYING TUNNEL, MOVING SAID DRYING STATION TO AN UPPER LEVEL WHILE REVERSING ITS RELATIVE POSITION TO THE HORIZONTAL, PASSING SAID DRYING STATION IN THE FIRST MENTIONED DIRECTION THROUGH A DRYING TUNNEL, AGAIN MOVING SAID DRYING STATION AROUND A LOOP ON THE CONVEYOR TO A LOWER LEVEL WHILE RETAINING THE SAME RELATIVE POSITION PARALLEL TO THE HORIZONTAL, REMOVING A DRIED ARTICLE FROM AN OUTSIDE HOLDER ON SAID DRYING STATION, AND MOVING SAID DRYING STATION TO A POSITION TO RECEIVE ANOTHER WET ARTICLE. 